Steve McGuckin, UK managing director of consultant Turner & Townsend, said: “The days of builders bidding for every sniff of work are gone.

“The confidence in London is now so strong that contractors are able to pick and choose their projects.

“Tender prices are still competitive, but with input costs starting to creep up this may not last forever.”

McGuckin was commenting on latest official construction figures which have been revised up to show 1.5% growth during the first quarter of the year.

That is more than double the original 0.6% estimate by the Office of National Statistics.

McGuckin said: “With such a big upward revision to the construction sector’s contribution to GDP growth, the industry can hold its head high.

“Its power to generate jobs and broader economic progress is undimmed, and construction growth has finally spread from the southeast to many other parts of the UK.

“But the long lag time between an investment decision being made and shovels in the ground means these output figures don’t yet fully represent the strong levels of activity at the front end of the industry.”